This invention relates to a rocking bolster wagon and, more particularly, to a four-wheeled vehicle wherein a non-rocking bolster may be provided for the rear wheels and a rocking bolster may be provided for the front or steerable wheels. Apparatus of this type is shown generally is U.S. Pat. No. 3,341,216 issued to John O. Bradford on Sept. 12, 1967, which is incorporated herewith by reference. The present invention constitutes an improvement over the structure shown in U.S. Pat. No. 3,341,216.
The rocking bolster construction as shown in the prior art Bradford patent provided an adequate structure to prevent tipping and promote stabilization of a loaded wagon. However, even with such structure, some undesirable sway is observed in "high gravity" wagons, i.e., wagons having a high center of gravity. Additionally, travel over rough terrain often results in movement or "jumping" of the rocking bolster from its support bar and subsequent impact of the entire weight of the wagon on the support bar and wheel axle or spindles. This produces damage to the axle or spindles of the wagon.
In an effort to overcome such difficulties, the improvement of the present invention was conceived and reduced to practice.